Valve refacing tool



May 21, 1940. 1.. -|MBLUM VALVE REFACING TOOL Filed Jan. 2, 1936 2Sheets-Sheet 1 IMBLUM INVENTOR ATTORNEY 2 Sheets-Sheet 2 W M U m 4/, I 2v w Z w IMBLUM INVENTOR ATTORNEY LEO M D WM 7, 6,

May 21, 1940. IMBLUM VALVE REFACING TOOL Filed Jan. 2, 1936 Patented May21, 1940 UNITED STATES PATENT OFFICE 1 Claim.

(Granted under the act of March 3, 1883, as amended April 30, 1928; 3700. G. 757) This invention relates broadly to a valve refacing orreseating tool, and more particularly to a tool by means of which thevalve seat is reseated positively concentric.

' An object of the invention is to provide a valve seat refacing toolespecially adapted to reface badly and eccentrically worn valve seats.

Another object of the invention is to provide a tool that is light andcompact, and that centers itself in a worn but serviceable guide withthe same accuracy as in one that is new and unworn.

A further object is to provide a tool of the character described thataccurately performs the refacing of valve seats in a minimum of time.

In the drawings:.

Fig. l is a front elevation of the valve seat refacing tool in positionon a valve port of an internal combustion engine;

Fig. 1a is an enlarged View showing the position of the cutter while inoperation;

Fig. 1b is an enlarged view showing the position of the rests while thevalve seat is being refaced;

Fig. 2 is a side view of the tool;

Fig. 3 is a section on the line 3-3 of Fig 1;

Fig. 4 is a section on the line 4-4 of Fig. 2,

Fig. 5 is a bottom view of the actuating handle in Fig. 1; i

Fig. 6 is a top View of Fig. 1; and

Fig. '7 is a section on the line 'l--l' of Fig. 1.

Referring more particularly to Fig. 1 of the drawings, my valve seatrefacing tool is shown in operative position on a valve port of aninternal combustion engine A, in which port is mounted the usual valvestem guide bushing B with a guide C.

As may be seen more clearly in Fig. 3, the head 10 of the refacing toolis provided with a bore I l terminating in beveled faces l2 and I3. Anadjustable casing I4 passes through the bore and is providedintermediate its ends with a bearing l5 so constructed that it will seatitself in the lower beveled face 13 thereby centering the casing in thebore. In addition to the bearing I5 the easing is provided wih a collaror bearing flange it that fits snugly in the bore to serve as a furthermeans to maintain accuracy in centering of the casing in the bore.Longitudinal adjustment of the casing is made through a cone member I!seated in the upper beveled'face l2 and resting against the bearingflange 16, the cone being held in position by a nut IS on the upper endof the casing that is screw-threaded to accommodate the nut. A dowel pinl9 fastens together the cone member I 1 and casing. The lower portion 29of the casing is tapered and receives exteriorly an expanding sleeve 2|provided with longitudinal slots 22 (Fig. 2). The sleeve is I tightenedon the casing by a nut 23 provided with wings or finger pieces 24(Fig. 1) that is in engagement with threads on the sleeve. When the toolis positioned for refacing a valve seat, the slots in the sleeve permitit to expand form- 10 ing a tight fit between the encasing valve stemguide bushing B and sleeve.

The head I ll is driven or rotated about the easing by a drive rod 25that passes through the casing and that is bent at substantially rightangles at its upper end to form a crank arm 26 that engages with avertical stud shaft 21 extending from a cover 28 for the head, the coverbeing secured to the head by any suitable fastening means 29. The driverod is operated by a crank 30 (Fig. 1) that is secured to it by a clamphaving a pivoted jaw 31 and a fixed jaw 32, in the inner surface ofwhich there is a groove 33 for the reception of the drive rod. The jawsare held together by a screw 34 against the tension of a spring 35 thatreleases the pressure of the jaws on the rod when the screw is backedoff. Although I have shown the crank attached to the lower end of thedrive rod, it may be desirable for some types of engines to place itelsewhere on the rod, which may be done without in any manner destroyingthe maximum efficiency of the tool. 36 is an oil packing chamber for thedrive rod and other associated parts, and 37 is a dust cover partiallysurrounding the casing to prevent foreign matter accumulating adjacentthe outlet from the oil chamber to the rod. Referring to Fig. 4, thehead is provided also with a cross-shaped cutter-bar guideway 38 whosearms extend at approximately 45 degrees from the vertical axis of thetool when in operative position. A similarly shaped cutter-bar 39 isadjustably seated in the guideway 38. A cutter 46], preferablyconstructed from tungsten carbide, but other suitable material may beused, is carried by an enlarged arm 4| of the cutterbar. Compensationfor wear on or depth of cut adjustment of the cutter is permitted by aslot 42 in the cutter, and the cutter may be positioned at variouslocations along the length of the en- 50 larged portion of the arm, asdefined by openings 43, to accommodate valve seats of differentdiameters. The cutter is held in position by a screw 44, and is heldagainst accidental slippage while in operation by serrations 45 in the 1The operation of the tool is as follows:

meeting faces of the cutter and cutter-bar (Fig. 2). V

The feed or adjustment mechanism to move the cutter along the width ofthe cut to be made is contained in an interiorly threaded bore 46 in thearm 4'! of the cutter-bar. A feed screw 48, having a bearing flange 49,engages in the interior threads of the bore, and the bearing flangerotates in a bearing cap 50. The bearing cap in turn provides a bearingfor a toothed wheel 5| that is actuated by a stud 52 mounted in anextension 53 of the nut l8. Each revolu" tion of the head around thecasing, a tooth of the wheel 5| comes into contact with the stud 52causing the wheel to turn a short distance about its axis. As the wheel5| is keyed to the feed screw 48 by key 54, the feed screw will beturned causing the cutter-bar to ride along the feed screw in adirection depending on the movement of the screw. The feed screwassembly is held in position by a lock nut 55. Moving parts of the feedmechanism for the cutter-bar are lubricated with oil placed in the lowerportion of the threaded bore 46, that is closed by a removable plug 56.

As a means to dampen vibration and to prevent looseness in thecutter-box, a plurality of friction pins 51, under pressure of a spring58, are placed in recesses 59 in the cutter-bar with their heads restingagainst the head ID, as may be seen more clearly in Fig. '7.

The head l0 and cover 28 are each provided with diametrically opposedfins 50 having bevelled edges 6| that act as guides to regulate the Pdepth of the cut to be made in the valve seat.

For example, if a cut .004 of an inch is to be made, the cutter is setso that it projects .004 of an inch beyond the bevel edges 6| that areseated in the valve seat, as shown in Fig. 1b. At the initial assemblyof the tool, the cutter head is adjusted so that the bevel edges 6| restagainst the valve seat and the lower portion of casing 20 is snug inexpanding sleeve 2|, these parts being seated together by light blows onthe nut 23. If, in the initial assembly, the edges 5| are not quitetouching the valve seat, turning of nut 23 draws in both casing 20' andsleeve 2| until the edges 6| just touch the valve seat as the cutterhead is rotated. As stated, the cutter is set at some predetermineddistance beyond the face of the edges 6|. As the head II] is rotated,the toothed wheel 5| contacting with stud 52 causes the cutter 40 totraverse in its path, which is inclined to the casing at approximately adegree angle, as shown, and first engage the outer edge of the valveseat, take a cut for one revolution, then move up an incrementcorresponding to a movement of the toothed wheel one notch, and so onuntil the whole face of the valve seat has been cut. The edges 5|continue to bear and rotate against the uncut portion of the valve seatand act as guides until the last of the seat has been cut. If thecutting has 5 failed to clean up the valve seat, the cutter 40 can berun back to the starting point by turning the toothed wheel 5| by handand drawing up nut 23 until the edges 6| are once more bearing againstthe valve seat, and the cutting operation repeated. The nut 23 alsoserves as a sleeve puller, in that when backing it oif, the beveledfaces 6| rest against the valve seat, and continued turning of the nutin the same direction will loosen the sleeve 2|.

At times it may be desirable to turn the wheel 5| by hand,in which eventthe stud 52 maybe Withdrawn from the path of the teeth of the Wheel bymanipulation of the knurled nut 62 attached to the stud.

It Will be understood that the above description and accompanyingdrawings comprehend only the general and preferred embodiment of thisinvention and that various changes in the construction, proportions, andarrangement of parts may be made within the scope of the appended claim,and withoutsacrificing any of the advantages of the invention.

This invention may be used and manufactured by or for the Government ofthe United States of America without the payment of any royaltiesthereon.

What is claimed is:

In a valve seat refacing tool adapted to be positioned within a valveport of an internal combustion engine, a casing secured in and extendingthrough the valve port, a cutter head mounted on one end of the casing,crossed guideways in the cutter head arranged at approximately 45 to thelongitudinal axis of the casing, a similarly shaped cutter bar operablewithin the guideways, a cutter tool adjustably mounted on one of thecross-arms of the cutter bar, a drive rod rotatably mounted within thecasing and having its terminal adjacent the cutter head bent at an angleto the longitudinal axis of the rod, a member carried by the headengageable by the rod as it is rotated for imparting movement to thehead, means mounted within one of said arms to impart movement to thecutter bar as the head is rotated, a star wheel mounted on the cutterbar actuating means, means carried by the casing for engaging the starWheel once each revolution of the head to intermittently actuate thestar wheel, and means mounted on the rod at its terminal remote from thecutter head for imparting movement thereto.

LEO IIVLBLUM.

